Total price is around $1,400 to $2,000 of ALL the parts, some places sell complete kits (including new clutch): stangparts.com
Of course that plus labor costs.
The cheap route is to hunt down all the stuff from a junker, the downside is you never know how the
tranny is.
When i did my swap i got all from a junker, the
tranny broke some months later but because of the torque of my engine, had that
tranny rebuilt to handle 330lbs (T5Z parts). I probably spent $1,800 total but i installed it.
I say go the EASY way, get a full kit..no hassle there. Even though stangparts.com sells used trannies they look at them before being sold so you know you get a good one.
One important note: you need a T5 with an ELECTRONIC (magneto style) VSS (speed sensor), GT T5s use mechanical VSS. So the
tranny must be from another V6.