personally as a buyer recorded/signed for really annoys me asit means it costs 95p extra which is for sellers benefit not mine, I do not mind if say over 20-30 pounds but for goods under £5 very annoying, mostly I just would not buy, but if I really wanted it I would buy but mark P&P stars down
signed offers nothing to buyer
with my other business seller hat on I still rarely used signed for below £30, it does not make economic sense, it annoys buyers and reduces profit, most people have budget for total so if willing to spend £7 if it costs 2.20 to post I have 4.80 to cover purchase cost packing etc, however if it costs 3.15 to post recorded I have only 3.85 to cover all costs a drop of 25% in profit
considering less than 1 in 100 parcels go missing it makes more economic sense to send standard and absorb cost of the very occasional refund, in over a 1000 parcels I have refinded about 6 as lost, a few more as damaged but signed for does not cover that
obviously as fergoose said if not trackable you will not win a not received case, you are under no obligation to send trackable as part of paypal; you just need it to avail yourself of seller protection
I send recorded/international signed for over about £30 and to certain countires (South/ central america and Asia) whatever the value
however I would add that certain categories do attract more missing item claims anything technology/ phones cameras computers, vouchers etc so I would take extra care in these categories as they attract more dishonest buyers rather than RM loses more cameras!!
if something unexpectedly makes a lot more than i thougt I pay for the trackable out of profit, you can not add it to bill later