Sorry for your loss. As Hobbyman2 said, the Facebook sales group titled "Shopsmith Sales Group" seems to be the best place to post these days for selling. The forum members are helpful both here or there. Once you know the pricing, etc. you can post on that Facebook group or even on Facebook marketplace. When you post, include pictures and explain what you are trying to do with it and why you are selling. Also, PLEASE post your location, even if it is just city name or zip code. A lot of people post and don't give their location, which slows down getting help. These machines are heavy so you are looking for local pickup or for someone to drive many hours to come get it. If you choose to sell some of the items piecemeal, such as some of the accessories or attachments, then shipping can get expensive, but some buyers go for this. If you are not on Facebook, then I would use Craigslist to post it.
So, the price will depend a lot on what equipment you have, the condition of it and WHERE you are located. Shopsmith equipment is very common in parts of the USA, but in some corners of the country it can be rarer, so the price will vary somewhat. The main (most common) Shopsmith machine is the Mark V, but these include the 500, 510 and 520 series of the Mark V. A newer Shopsmith machine is the Mark 7 which has a DVR headstock called the PowerPro, but the 500, 510 or 520 series could also have a headstock that has been upgraded which increases its value. Somewhat less common (fewer manufactured) Shopsmith machines were the Mark II and Mark VII and before Shopsmith became Shopsmith, Magna Corp created the predecessor the 10E/10ER. If you post pics here or on the Facebook sales group, members can help you identify what you have and try to help you on pricing. A general comment is that Shopsmith Mark V's that are used often sell for $500-1000 around most of the country. This can be just the machine, but often times the seller throws in accessories like bandsaw, belt sander, etc. Newer Shopsmith's, particularly ones with a PowerPro headstock will sell for more than this.
Here are a few links that may be helpful to you in identifying what equipment you have and how old it is. Also, there should be a plate on the side of the headstock with a serial number, which will help you date the machine as well. Best of luck on the sale.https://www.shopsmith.com/ownersite/toolhistory.htmhttps://www.shopsmith.com/ownersite/serialnumber.htmhttps://www.shopsmith.com/mediawiki/index.php/Main_Page