There's a lot of things to consider when buying fitness equipment as well with making sure you know what you are buying the equipment for specifically. Knowing what you're looking for and what you plan on working on is most of the battle of finding a piece of equipment that you want, thats why #1 is:

1. Consider your Needs

The equipment youre looking for should always be able to satisfy your needs in whichever way that may mean, you may need for it to fit in a relatively small space so you need to find a smaller piece. Also you are going to want to make sure to yourself that you know you are going to actually use this equipment that you buy, because often times you pay for what you get.

2. Consider the Price

Some fitness equipment can come off as very expensive to the naked eye but when it comes to heavy weights and machines that are meant to leverage these weights across an area its often a safe bet to go with the more known brands that sell more expensive products but for good reason. It all matters on your budget and what you need out of the piece of equipment, you may not be lifting all that heavy weight so you may not need a very expensive piece of equipment.

3. Consider the Space

This was mentioned in the first a touch, but the space is an obvious important factor as fitness equipment generally takes up a fair amount of floor space that it needs to make sure its stable with the weight that its holding. You need to be realistic about the room you have for something and you may even need to measure it so that you can read up on the specs of a certain piece and know if it is going to fit where you need that equipment.