To be fair you can build (an admittedly terrible) C-rated cargo hauling Asp for about 12m but I know what you mean. Having said that, if I can avoid dying when interdicted in my T9 which even with level 3 dirty drives has a phenomenal boost speed of 240, I'm sure I could avoid it in the afore-mentioned Asp which is considerably faster even with 5C thrusters equipped.
The point that so many people seem to not be getting here is that there is nothing about surviving interdictions that require you to do any fancy flying. You literally just zero throttle to submit to the interdiction, boost once, select your jump-out system and engage FSD. In the vast majority of interdictions (I'm talking about well over 95%)even in my T9 the npc will simply not have time to even get a shot on you before you are out of there.
The one and only 'skill' or piece of knowledge that's needed is to always fly with a jump out of the system plotted, i.e. when you arrive in a system, go to the galaxy map immediately (not after you've fuel scooped and started flying towards your target) and click to plot a jump to the nearest system. You can then still select your target station or planetary base to fly towards in the system you're in just like always, but if you get interdicted you only have to press the next navigation point hotkey to immediately target your jump-out system.
Pretty much every video I have ever seen of someone dying to an npc interdiction includes them frantically scrolling down the system list in the left hand panel to target somewhere to try to jump out to, all whilst getting shot to pieces. Usually with two pips in weapons, engines and shields for added fail. Five seconds spent on entry to a system setting up your escape is not a lot of work compared to a 10m+ rebuy.
The problem is not the npcs and it's nothing to do with needing engineered ships either. If I can get a T9 out of an interdiction without taking a shot using this method, people can do it in any ship because there is nothing slower.
What you say is completely valid & good advice, however I'd like to add a few extra caveats. Not to argue your point, but hopefully to add to it.
Lets take a long haul example; you leave the station & jump, jump, jump & eventually reach your destination system. Now during the jump phase of the journey interdictions are pretty easy to deal with, just as Red Anders says. You either circle in supercruise while charging the FSD for the next jump, or you submit & high wake taking minimal damage if you have your wits about you. Only basic skills required, but pay attention to your surroundings.
Then you have the final part of the journey, from star to station. If you see the 'that's the ship I'm looking for' message, you are going to have to deal with it, so anticipate & plan. As soon as you can, head away from the star in a random direction, open galmap & plot a route to another system (I use my first bookmark, it's just the quickest way to plot a route. It doesn't matter where, as long as you have enough fuel. Back out of galmap & reselect your target station from the left nav panel, now you have both destinations plotted. From supercruise press next target (I have mine assigned to 'N') if you want to jump out, otherwise continue to the station. If you drop to normal space for any reason, your high-wake target will automatically be selected (provided you used galmap & not the nav panel). Select 240 on the distributor too.
Avoiding local pirates is easy enough, just don't go straight from star to station, instead take a big arc above or below the plane of the system. This won't solve the custom NPCs, but it will avoid the locals. As you get close to the station make sure you have checked out all the locals in supercruise, noting any that fly towards you, and watching to see if the loop round behind you. Don't run straight for the station, spiral in, or overspeed past to see if you can get them to hit a local planet etc. At this point it not longer matters whether it's your Custom NPC or a local, you are in the same boat.
Assuming you were unable to evade the interdiction, your next step (during the interdiction) is to select highest threat (I have mine mapped to 'G') to show who is interdicting you. If it's a local you might be lucky & it'll be some low ranking thug that you can win the interdiction against. If you don't think you can win it don't panic, just follow the target as well as you can & zero throttle ('X') to submit.
As soon as you are in normal space (you may need to wait for the spinning to reduce if you failed the interdiction) boost, boost again & change the distributor to 420 (full power to shields). This is where the skill starts. Panicking won't help, you planned for this earlier.
Now you are going to put your prepared plan into action, as soon as the cooldown has finished start charging for the high wake, no need to worry about lining up with the target immediately, but be aware of where it is. Personally I never high wake in this circumstance, but I am always ready to.
Describe a smooth arc in the direction of your high wake target, do not slow or suddenly change direction (which will slow you down). If you go straight you are an easy target, you have 15 secs to line up with your escape, so no need to rush, and at a moments notice you can line up & just boost again to jump.
You have a faster ship - you will be out of effective weapons range soon enough & can simply cancel the jump & let the police handle the miscreant, or wait for a few minutes after they have dropped off your probably D-rated scanner.
You have a slow but manoeuvrable ship - you can joust them while the FSD charges, taking as little fire as possible. FA-off, pull up, wait a sec then boost, FA-on again to turn even quicker. If you are doing well let the Police distract/kill them, if you are doing badly line up your target & jump away.
You have a slow, worse manoeuvring ship with big shields & armour - Joust & ram, don't deploy hardpoints, it will cancel the FSD charge.
You have a slow, worse manoeuvring ship with poor shields & little armour - pray that your jump completes in time & try to learn not to be so greedy with your cargo capacity.
If your destination system is anarchy no Police will come & you are on your own. Consider your survival chances & maybe find another destination.
I'm far from the most skilled combat pilot but I can run away like a pro. Have a plan of action, don't panic, win the game.
