You will not find a good 20B for less than 4k-6k, that's not even with the transmission. 99.9% Jspec import place have no warrenty of rotaries what so ever. A 20B swap in the car and cranks runs about... 20k, that's without installing fees. Also if you have been researching this swap you also know you will have to run a single turbo setup and get rid of the twin turbo, seeing that the twin turbo setup doesn't fit in the engine bay, that's about 2k. Plus you will need a standalone like Haltech because the 20b or the n/a will run the fully custom engine setup you will need to make the car run, another 1-2k. Then there's the fuel, have to custom make your own Engine mounts and custom cooling lines, upgraded radiator, ignition, etc. I could go into the whole detail of how to do this seeing me and a friend done 2 of these swaps, but i'm too lazy. Here is an idea though....

20B engine $4,000
Engine mounts $500
Custom Turbo exhaust manifold $700, seeing that the win wont work
Turbo T72 $1,500, whats the point of doing this swap and then downgrading it with a crappy 500 buck turbo.
Oil/water lines (for turbo) $200
Intake pipe (for turbo) $100
Custom Downpipe $100
Exhaust system $800} This might be optional. If you already have a (larger) aftermarket exhaust system, this might not be necessary. $500 average for a good "cat back" exhaust, and $300 added for a pre-silencer section to be made.
Front-mount intercooler $1,200 3rotors puts out a heatload of heat under boost.
Oil cooler lines $200
Upgrade radiator $500
Custom radiator hoses to fit the 20B inlet/outlets $50-100
Cosmo water pump + housing $300
MSD coils $200
MSD DIS-4 $700
Bosch upgrade fuel pump $200
SS fuel lines and fittings $500
SX FPR $200 Required to control fuel rail pressure
Fuel filters $100 You'd be crazy to not run fuel filters.
Haltech E11 $2,000
Front anti-sway bar $500 Needed the handle the extra weight on an N/A car.
you can see that's way over 10k right there without transmission pricing.

But you said you can do a 20b for around 2-3k seeing that your family can help you out. So when you get it in, post some pics. I would love to see a 20B swap that runs with less than 7k spent.