First and foremost, if you are spending money on a piece of industrial equipment, it has to be able to do the job you are buying it to do. This may seem like stating the obvious but a lot of the time people put price before functionality and end up buying a machine that doesn't do what they need it to do just because it was the cheapest. If you are producing a certain amount of product each day that needs wrapping it is not much use if your stretch wrapper can only wrap half of that amount in a day!
Is the quality of wrapping going to be good enough to ensure that the products are protected in transport?
The last thing you want is for a pallet load of products to move in transit and end up damaging themselves and surrounding pallets due to insufficient pallet wrapping. Make sure that the pallet wrapper you are planning on getting puts the right amount of wrap onto your products and is suitable for the type and shape of your products.
If something breaks can you get hold of spares easily?
If the motor is an SEW Eurodrive motor, the pneumatics from Festo and the sensors from Omron than it is highly likely that you will be able to find someone local to you who either stocks the part you need or can get it for you. If, however, the above parts have been sourced from obscure manufacturers to keep the cost of the machine low then you may find it difficult to source spare or replacement parts.
If buying used has it been looked after and properly serviced?
When buying anything used you have to make sure that the previous owner has looked after it properly and had it adequately serviced, pallet wrappers are no different. Speak to the seller to see what work has been done to it recently, try to get a feel for their maintenance schedule, any information on when it was last serviced and what new parts have been fitted.