1500 to make what.. almost 150 more hp than what the motor was made from factory to run.
gt28.. i doubt would push 350-400hp very efficiently.
stock block 350-400hp would be pushing it.
what are you going to tune it with?

you're debating to sell the 240 or buying a honda.
dont see where the turbo fits in, but yeah.

what you listed on there will run you more than 1500 including a tune.