Anything Hanna or blulab will be accurate. Lots of cheap choices but ya get what ya pay for.

I use an EC meter from HM digital and wasn't that expensive at all. Works great. The little bit of extra accuracy you may get from a more expensive one, IMHO, isn't worth the jump in price. This isn't lab research for publication. Durability is the most important factor and some of the cheap ones don't last that long but this hasn't been the case with HM one I use and if I remember correctly it was only like $35. Been using it for over a year, no issues.