I am not aware of a machine that is in the same price range and has all of the features that the Glowforge has. Depending on what you are willing to give up, there are some options though. For the most part, I am going to try to stick around the price point of the basic. The biggest thing you are going to give up across all of these options is the intuitive software. To my knowledge none of the other laser cutters in this price range have an internal camera to help you align your design to your material.
If you are willing to give up the auto-focus and willing to spend the time to build the laser cutter, you can actually get a larger print bed. Further Fabrication made a wonderful series on not just designing the laser cutter but also on building it. You can also go to his website and pay a few dollars for the detailed plans and materials list. If you feel adventurous, you could increase the bed size to any size you want. For example, you could build it to accommodate standard 4x8 material from the big box stores.
You also have K40 lasers. I don’t really recommend these because of how much trial and error there is here. I am not referring tot he trial and error of cutting something out but rather the quality of the parts and needing to replace them. But after all the trial and error is done, you would probably have a laser cutter that costs a little less than the Glowforge but at a serious cost of your time and potentially material.
Full Spectrum has a line called the FSL Muse Core which bases around the same point as the basic. One of the things I find interesting here is that they give you the option customize everything, like to just upgrade to a 45w laser. They also have an option to have a riser to put a rotary in. I guess the bottom comes off for the riser.
Your best option might be to try and find a used Glowforge someone is trying to sell.
Have you tried to apply for a small business loan or anything? They may be able to help you with the amount of money you need.