Motor work is not easy. You will have to at least sub out the machining and I would encourage you to sub out the shortblock as well to get proper clearances etc.
1500 is way low, I spent more than that on rods/pistons alone. Then you have all your bearings which is another 2-300, headstuds another 2-400, headgasket, 100, engine gasket kit, 300ish (minus headgasket), you should do main studs, another 400 or whatever, then springs are 300....the list goes on and on.
I would put the price of your shortblock assuming your block was good much closer to 4000 and you would be wise to sleeve it rather than overbore your stock sleeves and hone them.
A built motor is not cheap at all, even with a good core. Have a number around $5000 +/- $1000 for a solid motor.
That doesn't include any bolt ons or other shit you will end up upgrading even.