In the UK we have the Distance selling regulations (act) which allows us by law to return anything bought FREE postage within a few weeks for a refund, allowing things to be tried out, such as eyepieces, do you.
Also if like me you are loyal to a reputable seller, with me it is the Widescreen centre who have been around for 30 years, I can ask Simon to try before I buy, do you have shops like this
https://www.widescreen-centre.co.uk