Glen, IMO the major difference would be that the Choate needs to have several holes drilled and tapped to be useful. The price for that would run about $20-30 per hole around here.
Add that into the cost and it makes the real price a good deal more than $34. DIY-ing that job, even if you happen to have a decent drill press, is a lot riskier than it might look at first glance.
Many SKS receivers are very hard and it takes a good deal of skill and experience, plus no small amount of luck, to D&T several 8x48 or similar sized holes in one without breaking a tool off somewhere in the process. Fixing that without inflicting further damage is difficult at best and, depressingly often, virtually impossible.
The typical receiver cover mounts are DIY-able with some care and patience. The keys to how stable and acceptable the result is, IME, are in how the tolerances of the mount and your receiver match up and the quality of the fitting work.
Generally, the easiest to get the most stable and repeatable result from that I've worked with in the genre is the B-Square. You don't get the 'quick change-over back to issue configuration' option of the others, but they're built in a way that eliminates most all of the common fitting and zeroing shortcomings of the others.
Let's face it: No matter how much time and money you spend on optics and mounts you aren't going to make a 'precision' rifle out of an SKS. You can make it easier for you to shoot it to the limit of whatever your particular carbine's potential might be, but it isn't going to do anything to improve on that in real terms.
How much time, money and effort you're willing to spend in pursuit of that is an individual call. IMO, in practical terms spending twice the money on optics and a mounting system is very unlikely to make the investment cost-effective for the difference in actual performance.
Just my $0.02.