what to do?

I am wanting to do my first rebuild myself, so I phoned for quotes on machining my 360 block.
With the whole package it comes to $950. Now if I go short block assembled balanced etc it comes to $1400 and I don't have to buy that part of the rebuild kit.What are the odds that on my first time assembling a bottom end that I will mess it up,as it is only a couple of hundred bucks for a pro to assemble?
I am going to go with a stock bottom end, Hughes whiplash cam, air gap intake, and I am going to try home porting my heads plus open the intake to 2.02.Headers will be cheap ones for now as I am on a serious budget and momma is already having a hard time accepting all this.
Any thoughts or advice on which way to go?
BTW these prices are all in C$. and taxes will be on top :pale: