Value wise they they are roughly on par. With Dboys items being sold in the lower 110-140USD areas and a TM DE in the 180-200USD area, coupled with the launcher, shells, magazine, charger and foregrip you are getting the better deal. No AV required to figure that out.
However when you think outside the box and compare usability, an AEG with 3 magazines and a grenade launcher can be far more useful than a GBB. However that all depends on who is wielding the GBB. As long as the AEG functions, I believe you are still getting the better deal.
"Its only a little bit on fire"