I have both cheap HF units, the $20 that goes on sale for $10, and just bought the $30 one on sale for $15 (but it rarely goes below $20).
The cheapest is very small, range is about freezing or so up to 240F I think. It is VERY handy and a great toy, but its view is wide angle (1:1) so it needs to be close for many things.
The $30 unit is almost mouse sized, doubles the temp range, has a laser pointer, and is I think 6 feet of distance for a 1 foot circle. So you could be a foot away from a hot radiator and spinning fan blade and read a 2" circle, basically its a practical working tool.
The around $50 unit looks like a pistol and is a bit better in all ways, but I felt no need to buy it, and prefer the size of the smaller units. I like having both too, as the little one goes in your pocket and should be fine for a lot of tasks, and the medium sized does the rest fine.
Worth the price of admission for two things alone, walk around your house and measure the temperature of the inside and outside walls, take it to dinner and measure the temperature of the food in the buffet.
