Try to understand question, you have answered all the question what you looking buy and you done good home work also price.
Your business accept what you try to replace, go for it, end it matter is its access switch for your client, as long the switch has support and you able to get smart net contract to replace when you have issue. it not matter is this excess stipck ..what ever to be honest.
every one like to save the costing so look for best option to protect business returns.
Thank you! My only hesitation with SG500X switches is the limited support ending in 2023. 3 years is good for ROI but current models such as SG350X and SG550X are offering 5+ years of support. I think SG350X is the way to go.