So, you have a few things mixed up here. Are you talking about the creditor or the debtor?
In your scenario, you would have to go to an investment bank (sell-side) for a loan or maybe someone from the IB has come up to you to solicit an acquisition. They basically run their financial models to determine your credit worth, economic outcomes and calculate their financial gains from the transaction. They base the loan rate on several factors (eg. type of loan facilitation, utilization, associate fees, term of debt repayment length etc). All this is based on standardized interest rates set by IBOR (Interbank Lending Rate). It's not as simple as buying a crib for $500k with a 30-yr fixed rate @ 3.25%. There's several different loans a PE firm takes on during an acquisition. But, usually the length of time a PE firm will hold onto an investment holding would generally be anywhere from 5-7 years holding period. An LBO (leveraged Buy Out) model will walk you through this in detail. Ideally, your IRR (Internal Rate of Return) would be 22-25%. Obviously, most acquisitions fall short of this, as well are significantly surpass it.
Now, from the Private Equity perspective (Buy-side), you're using tons of leverage (debt) to make these acquisitions. You run your own models to gauge what your economic obligations will be for the transaction and what your expected returns will look like. But at the end of the day, you're ultimately the borrower. This is what I do for a living. My firm invests in companies (usually small-cap), we help them grow and develop. Usually we target growth sales, or eventual IPO maturations. These are the divestitures we're principally focused on.
antidope
works for the Investment Bank I used to work for and started my career in as an Analyst for TMT Investment Banking. We have a lot of transactions as his bank is the left-lead (main creditor) for most of our acquisitions. He could probably give you a better idea of what their practices are, from an internal perspective.
But, if I had to make a guess...PE firm makes an acquisition for let's say $3b. At the end of it all, the Investment Bank will come home with close to $30-50m in fee revenue generation.