I would have a knowlegible Rep. come in and look at your application. What brand and grade (compound) of wheels that you are using and make a recommendation of which compound is best for you. It will vary with lift type, tire/ wheel type, application and even the bearing could cause pre-mature failure. If you are using good grade of load wheel, but cheap bearings, they could be creating extreme heat and causing pre-mature failure. Just an observation.

I have to agree with the earlier post that suggests you get what you pay for. Most forklift users miss the fact that often the labor to install the tires and wheels contributes significantly and in some cases exceeds the costs of the replacements parts.

Cheap wheels often fail prematurely and require additional replacements that bring with it additional labor costs.

Your objective should be to discover the longest lasting wheel to ultimately reduce your overall costs.

Try Mas Poliol in Madrid ;)

Sorry but the terms "best & cheapest" are in total conflcit with each other and do not go hand in hand. You get what you are willing to pay for.
A better way to look at this project total value - warranty coverages, reputations of the supplier, local installer response time when you have a critical need, local inventory on the shelve options that may fit you operations better to give you long life, improve safety, etc. etc. etc

Start by making a spread sheet and make teh decision from there