I just finished building my shop. Here are some things I found I needed:

GOOD Hobby Saw & Miter Box ($15)
X-Acto knife with LOTS of #11 blades ($25 knife and 100 blades)
Single Edge Razor blades ($3)
Metal straight edge rulers 36" and 6" ($15)
Small metal T-Square ($8)
30 and 45 degree triangles ($6)
Small and Medium T-Pins ($5)
Clamps ($.25 each)
Rubber bands ($4 for a BIG bag - Office Depot)
1/8" Brass Tubing - Handy for making small hole saw and more ($2)
150 and 220 Sandpaper ($3)
Sanding Block (Make it!)
CA (Medium and Thin) ($4)
5 and 30 Minute Epoxy ($12)
Wax paper (Stole it from the kitchen!)
Blue painters tape ($2)
Drill bits 1/16" thru 3/8" ($15 - Home Depot Sale)
Pliers - See Below
Tweezers - See Below
Small wire cutters ($15 for a nice 5 piece set at Home Depot)
Small Hammer ($6)
Shrink Wrap Tubing ($3)
Soldering Iron ($15)
Heat Gun ($12)
Sealing Iron and Sock ($13)

I'm sure there are lots more, but that is what I found I was running out and getting on the way home to do something right. Take my word on it, get the right tool for the right job. It will make your model 100% better in the end. I am building a GP Extra 300S. It's my first model, and I am planning on taking as much time as it take to do it correctly the 1st time.

Also, I found that if you get the "White Peg Board' instead of the brown stuff, it brightens up the shop bench and is worth the extra $3 a sheet. I got mine for about $13 for a 4x8 with 1/4" holes.