Infrared, aka IR, is the way to go imho. I bought a Micro Temp MTPRO, 11:1 and up to ~ 950F last season when I began to doubt my third mag stove top thermometer. Price isn't exact but I think it was ~ $45-50 delivered. There are cheeper uints available. I don't think the ratio is that important if you keep it in mind when you use it. The mag calibrated okay at 210 suspended in boiling water but the fires looked/felt hotter. Turns out it was reading low by about 20+% compared to the IR unit. I use one at work that is NIST traceable and they read identically. Not only can I tell the stove and pipe skin temperates (from my chair - is there any other way?
) but I've found and sealed a lot of little leaks around the doors and windows. Also used it to balance my AC this past summer. Great tool.