Can I suggest something to resolve the quandary, then?
With your basic scanner, fly to the TRAPPIST-1 system. It's Unexplored and uninhabited, but contains an ELW, as well as some HMCs. You should get about a million credits if you scan the entire system, and the entire system is easily within range of your scanner. While you're there, marvel at this compact little planetary system, which made the headlines a year or so ago when it was first discovered in-real-life, and added to the game very shortly afterwards. Now go somewhere more than 20 LYs away from TRAPPIST-1, and sell your data.
If after this you still don't yet have enough cash for an Advanced scanner, try the Fomalhaut system next. It, too, is an Unexplored system only a few tens of LYs away from Sol, with an Earth-like planet. The ELW is over 2000 Ls away so will be outside the range of your scanner, but unlike TRAPPIST-1, the Fomalhaut system is inhabited, with space stations all over the place. There's an orbital station around the ELW, called "Dobson Terminal", and orbiting space stations are always visible on the system map. Select this station, fly towards it and honk the scanner once you get within 500 Ls of the station. You can now see and scan the planet. Feel free to do this to scan the other planets in this system, too; there's a few HMCs and a couple of Class II gas giants, which are the most valuable type of gas giant, though one of them is quite remote.
Sell the data from Fomalhaut and TRAPPIST-1, and you should now certainly be able to afford an Advanced scanner, and maybe some cash for a few other things you might need while exploring, like a good fuel scoop and an AMFU.