Generally speaking, a 2005 Honda Accord turbo kit will cost somewhere in the ballpark of $1,000 to $3,000. The exact price will largely depend on where you’re buying the kit from, the contents of the kit, and the quality of the kit itself.
If you’re looking for something on the cheaper end of that spectrum, you might consider buying the Universal Honda High Performance Turbo Kit from the SaferWholesaleSite for roughly $1,200 (after taxes/shipping). It’s meant to be compatible with all Honda models and offers a good starting point for turbo modifications.