I go to a university. And i have to bring my computer back and forth. It's a quarter system so I have to carry my computer back and forth multiple times a year. Also, dorms and the provided desks had limited space. This is purely anecdotal and may not apply to you but I thought I'd chime in: I highly highly highly recommend mini-itx form factor. If you want to go single gpu, it's totally doable without any sacrifices in performance.
PCPartPicker part list / Price breakdown by merchant
| Type | Item | Price |
|---|---|---|
| CPU | Intel Core i5-4590 3.3GHz Quad-Core Processor | $159.99 @ Micro Center |
| Motherboard | Gigabyte GA-H97N-WIFI Mini ITX LGA1150 Motherboard | $91.99 @ SuperBiiz |
| Memory | G.Skill Value 16GB (2 x 8GB) DDR3-1600 Memory | $99.99 @ Newegg |
| Storage | Crucial BX100 250GB 2.5" Solid State Drive | $80.98 @ Newegg |
| Video Card | XFX Radeon R9 290X 4GB Double Dissipation Video Card | $289.99 @ Newegg |
| Case | Zalman M1 Mini ITX Tower Case | $69.99 @ Newegg |
| Power Supply | Corsair CX 600W 80+ Bronze Certified Semi-Modular ATX Power Supply | $59.99 @ Amazon |
| Monitor | Acer G227HQLbi 60Hz 21.5" Monitor | $100.98 @ Newegg |
| Monitor | Acer G227HQLbi 60Hz 21.5" Monitor | $100.98 @ Newegg |
| Prices include shipping, taxes, rebates, and discounts | ||
| Total (before mail-in rebates) | $1134.88 | |
| Mail-in rebates | -$80.00 | |
| Total | $1054.88 | |
| Generated by PCPartPicker 2015-04-25 06:56 EDT-0400 |
PS: Do you care about how loud your system is? If you do swap out your stock intel cooler for a name brand low profile cooler. Also, if you do want mini-itx, really do the research on which case you want. Graphics card length and width are really big issues with mini itx cases.