They will last really well compared to the steel ones but there are plenty of Chinese made tungsten carbide bits to fit Dremels that are much cheaper, I’ve been using them for years and they are pretty indestructible. More on reddit.com

Just get some cheap diamond burr bits and maybe a set of tungsten carbide bits that’s all you need at first Diamond burr: ZFE Diamond Burr Bits, Diamond Burr Bits Drill Kit for Engraving Carving Rotary Tool- 1/8"(3mm) Shank Pack of 90Pcs/ 3 Sets https://www.amazon.com/dp/B016HUCKSG/ref=cm_sw_r_cp_api_i_13nKFbE9AGWW5?_encoding=UTF8&psc=1 Tungsten Carbide: Double Cut Carbide Rotary Burr Set - 10 Pcs 1/8" Shank, 1/4" Head Length Tungsten Steel for Woodworking,Drilling, Engraving, Polishing by YEEZUGO https://www.amazon.com/dp/B07S8WRYH4/ref=cm_sw_r_cp_api_i_54nKFbF44TVMS Diamond burr is all around good and good for detail and tungsten carbide is good at remove lots of material and getting a rough shape More on reddit.com

Have a look at the bits here. Not exhaustive in terms of what's available - I've seen a much better Dremel chart on here explaining all available bits,but this will help. The bits aren't bad either. link In terms of what do I prefer, it depends on what material I'm working with. I found that the diamond bits (designed for engraving) are actually quite good at shaping wood and cork, giving a neater finish that the carbide milling bits. I like using cutoff wheels for cutting plastic and sanding bobbins are great for finishing / smoothing. For enlarging holes in plastic, a cutting drill bit is also effective. More on reddit.com

The smallest engraving bit I use (of a similar design) is 1/32" (about 0.8mm) at the tip, with a cutting depth of 0.015" (about 0.4mm), and I expect it to break every time. Also carbide, cutting hard plastic. The tip is effectively 0 rpm, so it's just pushing through the material. I would go really slow with really shallow passes to have any hope. More on reddit.com