||A big part of that number ($7-$8K) went to fixup parts
like trim and paint, etc. Also I paid a big premium to purchase a $7K plug and play LOJ swap kit. Doing it again, the second time, I'd expect to pay around $20K. Even if you used less desirable parts like an iron block and/or used mechanicals; and add to that if you could do your own fabricating and welding, It'd still be difficult to replicate this for under $15K.
Lots of kids on the FB LS/ Nissan Page claim they're going to finish theirs for under $10,000... but of course, they're not even close to seeing the home stretch... and when they finally do get it done for under ten grand, it won't have AC, no creature comforts, I'll be 20 year old bad paint and a crap interior. Heck by the time they're actually finish, the inflation rate will have wiped out any cost savings they might have realized by doing it their way.