I don’t know Meade scopes so am unsure what the LX3 200 is. I presume an SCT on an alt-ax mount, 8″? 10″?
Prices will greatly depend on condition, specific type/model, accessories and any problems. Looking online, I would suggest ball park figures for an 8″ would be in the region of £400-700; 10″ £600-900; 12″ £800-1200. But it is only worth whatever anyone is willing to pay for it. My observations are that fork mounted Meade telescopes were once very popular, but desired less today by people buying second hand telescopes. I may be wrong.
The other option is to talk to someone like Rother Valley Optics and see if they are interested in it to sell on.
James