Is this a good deal?
 

just curious seems cheap
http://cgi.ebay.ca/Marui-Version-2-G...QQcmdZViewItem

http://www.airsoftcanada.com/showthread.php?t=44466

Better deal.

isn't BOYI stuff crap? aren't most TM internals besides the piston crap?

^^ lol oh burn =\

TM internals, as far as stock internals goes, are some of the best around. The gears may be a bit softer than G&P or CA, but besides that, all the other components are pretty good, especially in the compression chamber. The air seal is definitely better than I've seen in some CAs, G&Gs and G&Ps.

So are these boxes a good idea for a backup box? whats the fps ?

The FPS will vary depending on the front end well mostly the inner barrel length. The one I linked above says it has a M-100(1J) Power Spring I'm not sure how that compares to a stock TM spring but if the CYl/CYLHead/Piston/piston head are different from a TM that will have an effect as well.
One plus is that it also says its a reinforced box so it should be stronger if you keep the stock internals you could put them in this box or some of them like the spring to maintain your FPS.
I wanted it to put in an MP5 that I'm gonna turn into a counter sniper with a M4 or M16 inner barrel so I was just looking for a V2 box with a larger CYL capacity to push the BB down longer inner barrel without suck back so an Armalite box was perfect.
That being said, the one for sale by Huang also linked above by Tankdude seems to be the same he could confirm this I'm sure and at the price even with our canadian buying power it is still a beter deal.
Also yes it would be a great back up box even if the fps is not what you want cause you could just swap out parts till you find what youy are looking for.
Go Huang Go!!