Wait...so you're going to charge the buyer the price you paid in tax??!! Why?? What logical reason does that serve other than your greed??!!
Look, your Spec B is VERY nice. Top notch, for sure. But let me let you in on a little secret: you cannot charge the full purchase price of your added mods to your vehicle. I've been in this community for about a decade and most folks want to help out their fellow Subaru brethren. I've seen brand new in box items go for less than the manufacturer's/retailer's selling price, simply because they know there's a phobia of someone else putting your ball-scratchers on a "brand new" item.
In 2007, I bought my 06 WRX w/ 14k on the odometer and about $10k in mods for $18k. I just sold that car with 85k on the odo and another $15k in mods for $14,500. I think I made out like a bandit. But, guess what...I didn't charge for the mods!! Blue book value for my car in the condition she is in (excellent) and the miles on her sweet chassis put her at $15k street value!
So, unless you have done zero driving on any of those $60k worth of parts, be honest, be cool and sell your car for what it is TRULY worth. Otherwise, GLWS and have fun being berated by those that know better.