I am going to go and purchase a dremel tool to carve out and make details to my future fiberglass/bondo helmets and armor........ So very simple question that I need a very professional 405th infantryman or infantrymen to answer!!
You first have to ask yourself how many of those "future costumes" you want to make and whether you have any other hobbies where a rotary tool might come in handy (which is unlikely, otherwise you would already have one, right?

). If you hardly have any use for it, spending a lot of money on a super-sophisticated model doesn't make sense.
Don't let Dremel's advertising fool you: You are almost NEVER going to use this thing "around the house". You can, theoretically, but let's be realistic: Dremels are too small for most of the advertised uses, they really only excel at small-scale crafting type hobbies. A Dremel will never replace a drilling machine or a palm sander.
The smallest model I'd recommend is the 300 series, although that is already more expensive than 50$. It has variable speeds though, instead of just on and off - that's going to be handy when you work with plastics, which tend to melt (and possibly ruin your accessory) if you set the speed too high.
Just for clarification: Accessories are the "bits" you insert into the front, like a cutter, attachments are things you can screw onto the front, like a straight cutting guide.
P.S. I have no bits or anything... so A kit might be best-- or just name me some bits I will need...
Kits often contain a lot of useless stuff (usually tons of felt wheels, cutting discs and grinding stones - i.e. cheap stuff, to get the item count up) and lack accessories that you really do need (selection of carving accessories, which can be more expensive). I'd recommend that you get the tool with as few accessories as possible, get one accessory of each category separately, try them out and once you have a feel for it get more. Don't buy stuff you
might need, only buy stuff that you
definitely do need.
You'll most likely need this:
- Dremel (300 or better, preferably a wired model)
- Flex shaft attachment (nice to have, but expensive)
- 4486 - Dremel chuck (makes accessory switching a LOT easier and quicker)
- Sanding:
- 407, 408, 432, 445 - large sanding drum mandrel and sanding bands in 60, 120 and 240 grit (last longer than small bands, but are more bulky)
- 430, 431, 438, 446 - small sanding drum mandrel and sanding bands in 60, 120 and 240 grit
- EZ402, 512E - EZ Lock mandrel and EZ Lock 320 grit finishing buff (useful for making glossy plastics slightly matte, otherwise mostly useless for propmaking)
- Cutting:
- 561 - multipurpose cutting bit
- Cutting discs, for example 540 with 402 mandrel
- Carving, detailing (mostly for details you can't achieve with sanding bands, pick your desired shapes and sizes out of the whole catalogue):
- High speed cutters like 193, 191
- Engraving cutters like 106