I am in the market to purchase parts to build my special rifle.

so far, i am thinking about these for my lower:

Stag Arms stripped lower receiver $85
RRA lower parts kit with NM 2-Stage Trigger group $140
+ 6 position stock from tapco for $49.99

with shipping and ffl transfer fee in mind, do you think I can get a better deal at a gun show or online?

also, is stag arm stripped lower receiver compatible with RRA lower parts kit?

Quoted: I am in the market to purchase parts to build my special rifle. so far, i am thinking about these for my lower: Stag Arms stripped lower receiver $85

Good price, good reputation.

RRA lower parts kit with NM 2-Stage Trigger group $140

Why do you need a 2 stage trigger?  Is this going on a SPR long-range precision rig?  

+ 6 position stock from tapco for $49.99

Cheap.  You get what you pay for.

with shipping and ffl transfer fee in mind, do you think I can get a better deal at a gun show or online?

No.

also, is stag arm stripped lower receiver compatible with RRA lower parts kit?

Yup.

I'd probably ditch the NM trigger and use the money you save on a normal Rock River parts kit for a Vltor Stock Kit as offered by some of the EE regulars.  But that's just me.

Keep the whole thing Stag.  Their LPKs, while more expensive than RRAs are nicer.  Of course this is with the single stage trigger.

Also, Stag's collapsible stock is Mil Spec, 6 position and inexpensive.  More than the Tapco, but definitely worth the extra $$$s

For about $20 more dollars, go for a RRA collapsible stock.  Nothing good has come from those Tapco stocks.  Or just get a Vltor or Magpul and be done with it.