My first T45 swap was done for right around $1200, and at that time, T45s weren't as cheap as they are now. If you search around for parts, and do all the work yourself, yes, you can definitely do the complete swap for under $1200, especially if you already have some kind of tuner setup. If you have to get an xcal or pay for a tune, then it will likely be more.
I'm putting together a parts list for my swap and starting to buy parts when I find a good deal, but I don't see how I can possibly get them for under $1200, although its not that far off.
Where did you save money based on my estimated break down?
Did you buy new parts for clutch, pressure plate, throw-out/slave, clutch master?
My 4.6 DOHC is stock and the only upgrades I'm really considering are a Cobra Intake and Cobra Intake Cams (both already purchased). I like budget parts, but I also don't want to have to replace parts possibly after 10-20k miles. I also don't want to go too budget on a used trans that someone abused in their mustang.
Clutch Pedal Assy - $200 (have - came with used master)
Hydraulic Line - $50
TR3650 05-10 Mustang - $550
Clutch/Pressure Plate Set $200-$300
TO/Slave - $50-$100
Trans Mount - $50
Modify Trans Support - FREE
Shifter $50-$200 (from used stock to aftermarket)
Custom Tune - $100
(plan on buying an SCT X4 for $400 - not including this cost, but it does not have a pre-installed Mark VIII tune)