Is it difficult to sell my practice and the real estate together?

It depends. From a tax perspective, lease payments are deductible, whereas the cost to purchase is deductible over 39-1/2 years. However, with the cost of interest on the loan during the early years being high, the majority of the annual payment will be deductible. With that as a background, the initial decision of whether to lease to buy is going to be based upon the buyer's vision.

Does the current space provide for ample growth opportunity? If the buyer feels that the space and location will serve him or her over the long term, they will then move on to the decision to evaluate purchase versus lease. The final decision to purchase versus lease will be based upon the cost to own
as compared to the cost to lease. If the cost to own is double on a monthly basis (monthly principle and interest loan payment plus real estate taxes) what the rent is under the lease, the buyer will likely not
desire to purchase the real estate at this time.  

The more reasonable the sale price, the more likely the cost to own will be closer to the cost to lease and then it is an easy decision for the buyer.