How much would the cost to do an engine swap for one?

GST is turbo you know that right? What engine. If its a GS its non turbo and sell it and get the GSX or GST

My friend has changed his engine twice, both times he did it himself so he only had to pay for the used engine which was less then $1000. You can find engines on ebay easily enough or try the partlocator.com. If you need to pay a mechanic to do the work, expect a bill of $1500-$2000 as it will take at least 15 hours to remove and install the engine.