Premature pool heater failure

My jersey shore heaters don't last long, they rust out. I'm talking about my Pentair 200k btu. this is for a 7000 gallon pool
My pool guy is recommending another Pentair. installed for 2300$. Is there a better more longer lasting solution.
the heater is outside by the pump and filter.

I can't afford to replace this every 5 yrs, oh and we like to keep the pool temp at 85.

Your post is missing some critical information:

1. Is the pool heater "rusting out" from the OUTSIDE, from ocean air and spray? Or, from the INSIDE, from salt pool water?
2. Is the "Pentair" pool heater, the Max-E-Therm models Pentair got when they bought StaRite, or is it some other product Pentair bought?
3. What do you mean, "can't afford to replace this every 5 yrs"? Really can't afford? Or just would rather not spend the money?

After all, in most cases the cost of INSTALLING a gas pool heater is less than the cost of OPERATING one for a year.

I'll make a few observations:

1. The Pentair StaRite is widely recognized as the worst major brand pool heater . . . except by pool dealers who are part of the Pentair 'kick-back' bonus program, if they sell all Pentair. (Bonus kick-backs are not a Pentair specialty; Hayward and Jandy do it too. It allows them to unload the bits of their product lines -- like the Max-E-Therm heater, or the Hayward chlorinator -- that are total dogs.)

2. BUT . . . if the problem is ocean air, the plastic case StaRite is likely to be most resistant available.

3. On the other hand, if the problem is salt water IN the pool, these Hayward heater are a much, much better choice:

Natural gas models:

• Hayward H400FDN Universal H-Series 400,000 BTU Natural Gas Pool Heater
• Hayward H350FDN Universal H-Series 350,000 BTU Natural Gas Pool Heater
• Hayward H300FDN Universal H-Series 300,000-BTU Natural Gas Pool Heater
• Hayward H250FDN Universal H-Series 250,000-BTU Natural Gas Pool Heater
• Hayward H200FDN Universal H-Series 200,000-BTU Natural Gas Pool Heater
• Hayward H150FDN Universal H-Series 150,000-BTU Natural Gas Pool Heater

Propane models:

• Hayward H400FDP Universal H-Series 400,000-BTU Propane Pool Heater
• Hayward H350FDP Universal H-Series 350,000-BTU Propane Pool Heater
• Hayward H300FDP Universal H-Series 300,000-BTU Propane Pool Heater
• Hayward H250FDP Universal H-Series 250,000-BTU Propane Pool Heater
• Hayward H200FDP Universal H-Series 200,000-BTU Propane Pool Heater
• Hayward H150FDP Universal H-Series 150,000-BTU Propane Pool Heater

4. BUT . . . if your heaters are "rusting out" from the INSIDE and you do NOT have a SALT water pool, THEN you are doing something wrong, chemically. Even the StaRite, as bad as it is, will last longer than 5 years if you maintain proper water chemistry.

If this is the case, your FIRST purchase needs to be a K2006, which you need to learn to use.

Once you've got it, and have several complete test results, we can look at what's going on that would cause heater failure. (And, no, your 'pool guy' probably does not know how to do pool chemistry 'right'. A few do, but most don't.)

Good luck!