A4 copiers are the smaller ones that don’t do 11 x 17 and therefore have a much smaller footprint. They range all the way from the $300 inkjet things for the home to commercial grade ones that cost a few thousand. Since they all look like how can you tell the difference since they have the same features; print, scan, and fax.
Begin with supply costs. If your volume is real low go to a store. If you’re a business with a higher volume than you need to do some investigating. We carry three lines of A4 copiers and the supply pricing is all over the place. As you know from your painful experience with inkjets; cartridge costs can be significant.
Most non-store sellers of small copiers can give you a pretty accurate cost per page so you can compare brands. The Kyocera line of smaller A4 copiers have very good toner pricing. Plus they come with a very generous three year or 100,000 page warranty on the expensive stuff.
Which leads me to my next point. Ask about warranties. Even if you take out a maintenance agreement a good warranty allows the dealer to price the maintenance agreement lower since he/she will be reimbursed for certain parts. You must buy from an authorized reseller to get the warranties though which is almost always a local dealer in your town. Manufacturers try to prevent dealers from selling into each others territories. They control that through their warranty program.
If your volume is real high stick with the larger A3 copiers. They will have lower operating costs and longer lasting parts. To keep the cost down look into a late model used copier. I recommend www.austinusedcopiers.com for that. They specialize in late model used copiers that are about 25% or original MSRP. The larger copier at the office or where you use to work is what I mean by an A3 copier since they can make 11 x 17 pages. A3 and A4 are European terms and are being adopted worldwide because of the global marketplace.