Steve - be very careful with Lasers - better half has had both a Universal from the states and now a Chinese one - Universal 80w was - +-85 watt - a magic control system - could reproduce photographs directly etc . Unfortunately it was burnt out by a very bad current surge and was18 years old, so Universal no longer had spares etc . Those are the Roll Royce of lasers with water cooled solid alloy cutting beds and aluminium Laser Tubes - unfortunately the price reflects that and we were not able to afford a new one . it was replaced by a Chinese one with Glass Laser tube , 60watt (about 55 in reality) - a 600/900 nominal bed actually 860/560 - bed is honeycomb metal - literally about the same size as real honeycomb but very difficult to clean if you leave it too long - unlike the Universal bed - engraving ability is not the best - photos are out for instance - everything must be drawn. It requires dxf (CAD) files for input to Lasercut 5.5 which is the controller software. We use Corel Draw. Cutting ability is not that great either - cutting 6mm perspex for instance requires 2 to 3 cuts , 6mm MDF about the same . Ply however is very easy , as is 3mm MDF , perspex , card , polystyrene etc. ABS gives off Cyanide gas which is not very good for you and Old LP's give off a highly corrosive gas which is bad for both the user and machine - which were both found out the hard way..........
We will be upgrading sometime this year to a 80w tube, and a new Taiwanese control system/motherboard which handles engraving better and takes direct input from Corel .Anything less than 60w nominal is a waste of time and can only be used for cutting card and other thin materials . If they have the old Lasercut 5.5 control system they are not much use at all because of the difficulty engraving. (yes you can engrave on thin materials). One of the other problems you have is that cutting/engraving is sometimes inaccurate to the extent when making model Willy's Jeep dashboards the engraving for the instruments decided to angle itself at 15 degrees and the steering wheels for Land-Rovers ended up twice the the thickness at the top than the bottom. In both case the files in question were redrawn in full but the problem still persisted..........Rather go for a minimum of 60w - reasonable sized honeycomb cutting bed and ensure it has one of the newer control systems - friend in Oz has a 120w but it has much the same problem as ours with the control system . A movable bed is not really a luxury either if you need to engrave a box or very thick material . A rotary attachment is however a luxury - ours has never been used - although the Universals was for glasses /bottles etc...........