A 10/22 is a pretty simple thing to build compared to a Mark I/II/III/IV.
The 10/22 receiver is a painted aluminum investment casting, for instance. The gripframe on the I-III was welded together from two stampings with the weld dressed so nicely that most people have no idea that's how they were made. The new one is CNC machined from a forging.
For budget, wait 'til the plastic 22/45s come out. My Mark III 22/45 is the 4" stripped-down version with fixed sights, manual windows, and rubber floormats, and it was under three bills back in '10; I think the last ones I saw were $299 or $325.