Just curious, how much did you score the trailer for? I'm looking at a used Ruger trailer and similarly doing a slow (and cheap) build. While an Xventure, Turtleback, or Patriot are nice trailers they are super expensive and if I'm spending $20-$40k on a trailer I'd like to be able to sleep in it. I'm somehow worried that once I start adding mods, electrical, RTT, awning, drawers/slides that it will easily put me into the $10-$15k territory which at that point is very close to teardrop trailer prices. Ultimately I guess if I can't do it cheaply then I'd rather just jump into a teardrop trailer.
Your train of thought makes total sense, and I'd also jump into an off-road teardrop if possible.
I would have liked a Ruger myself, but the options here in Canada are very, very limited, so I took what I could get. Paid $8k CAD, (about $6.1k USD right now) which is a pretty decent deal, especially considering the tent itself would run $2-2.5k CAD. This tent also seems to be no longer available, and I'm happy I have it, as it's the roomiest floor plan and the best option from FSR (for my needs).
The mods do add up real quick. So far I'm into (all prices CAD):
~$500 for spare wheel & tire
~$600 for custom aluminum work
~$200 for custom stainless work
~$180 for the basket
~$70 for tongue box
~$700 for the two front runner cross bars (getting these to Canada was stupidly expensive and not something I'd do again)
~$350 for electric drum brakes and wiring
~$25 for turnbuckles
~$40 for misc hardware
So nearly $2.7k CAD sunk into it already, not counting around ~$200 worth of hardware I already had on hand (80/20 materials, skateboard bearings, nuts/bolts/washers/etc).
For comparison, I could order a Smittybilt trailer kit for $10,273.99 CAD (plus taxes, possibly other costs). The Smitty comes with a lot more out of the box, and I think it's generally more useable, due to larger openings, pre-existing slides, already coming with the spare, tongue box, etc. But with the Smitty I'd lose the Timbren suspension, have to wait a few months (goodbye summer), and still have to buy a RTT on top of the price. Win some, lose some. If I were buying in mid winter, I'd probably have gone the Smitty route, but buying in the spring and having the FSR option in front of me, that was more appealing.