Sounds like you're looking to time the market, not necessarily value your specific property.
For that, you want to look at 3 metrics. Median sales price (not average!), Cumulative Days on Market (CDOM), and Months of Inventory. Ideal time to sell is when sales prices are climbing/peaking, CDOM is at a minimum, and months of inventory is low (sub 3 months in a small market)
Unfortunately local Realtor associations and their MLS don't make these stats readily available in a lot of places. The stats you can see on Zillow, Realtor.com, etc. are typically pretty inaccurate for small markets.
I'd call around and get lined up with a savvy agent that understands analytics and have them do the legwork for you. If you can find an agent that works with investors/developers, you have a pretty good chance they're dialed in, and numbers/results driven instead of chasing listings. You have to remember that the vast majority of agents are part-timers, but the good ones are worth their weight in gold, and can easily get you tee'd up with the goods. If you ask an agent for the 3 metrics above and they don't a) know immediately off the top of their head, or b) send you a data set illustrating them in real-time, move-on.
I pay for all my clients to have access to Homebot.ai so they can track all kinds of metrics, both property specific, AND market wide. It's badass. Might be able to track down an agent with those capabilities if you ask around as well.