So, my market of choice (corporate bonds on amx exchange) is not very liquid, but has designated market makers who are obliged to submit daily quotations. For example, most traded amd security last month is [AMAMRBBN2ER0](https://amx.am/en/instrument_page/AMAMRBBN2ER0/historical): stunning 17 trades in a month! And a whole 50 trades in last year. But the bid, ask and spread are pretty uniform and you are guaranteed to buy/sell your bonds at fair-ish price (maximum spread is 5% by law, e.g. if the ask yield is 8%, then bid yield shall not exceed 8.4%).
Basically, most of the time I (and other investors) just accept marketmaker's bid/ask price and trade at their conditions. However, I recently experimented with limit orders slightly above marketmaker's bid and below their ask. Well, it needs at least a couple of days to work, but they do eventually fill.
But I have a question here: when the trading is mostly sporadic, how do I calculate opportunity cost here? Like, let's say I want to buy abovementioned AMRBBN2 on 24.12: I can guaranteed buy it today for 100.4377 (8.9049% ytm), or I can place an order for around 100.205 (about 9.35% ytm) and wait god knows how long for it.
How can I try to predict, will the wait worth the difference in price? Are there some standard practices and approaches for illiquid markets, and what can I read about how it usually works in theory? I'm not sure if this could be timed, but if it could, how do I analyse when it's the best days to trade?