That is correct. Look for specifications about the sealer and compare those years and see if there is a stated number of years between sealing.
Price doesn't mean anything. For example, I undersell MOST industrial powder coatings by a minimum of 20 percent which on a skid of that product is about 800 dollar savings.
The powders that I recommend are ALWAYS far superior to what they are using and they cover more square fooage in addition to being less money... It's a win-win.
Name brand recognition does not mean it is good or the best. A lot of it is HYPE.
I always look at the chemistry.. Then I compare the important data and lastly I check for pigment and resin content.
Sealer in a wet product is same as a clear coat in powder coating. It seals... It protects.
A little bit of homework will pay huge dividends for ya De!