Another angle you may wish to look into is the partnerships with hotels and employers. When I am away on business, i am only allowed to make arrangements with certain hotel chains as my firm have special rates/agreement.
Personally I don’t believe there is no level to how low you can go when it comes to budget hotels, especially when the money is funded by the employer. In my experience, the bigger the firm the lower the travel budget and stronger restrictions regardless of position. In my experience technology firms are the cheapest of all. If you can try and get a copy of corporate travel policies and budgets by different types of employers and compare them.