Products supplied by us are like long distance runners. We find the cheaper products on the market are more like 100 meter sprinters, fast over a small segment of time. Where as our products last and have endurance over a long period of time. Some of the cheaper products run fast for a short timescale but could eventually grind to a lower level of output than stated. 

Try imagine a 100m sprinter running a marathon.

We know this from our reliable manufacturers. Providing products that have lasted the test of time over the past 35 years, with a much lower degradation over two decades than others could drop over a much shorter time, explaining why they have much higher extended guaranteed performance targets. 
In the long run it is more beneficial to buy higher quality Solar Panels as the maintenance costs are virtually nil. You will see a much larger return on your investment for a much larger period of time.