Using Seller's Title Company Because They "Already Opened Title"

[David Seale]

Newbie investor here and am uneducated on the choices I have for a situation I'm in.

I've always heard that the title company of choice used in a real estate transaction should be up to the buyer and that the buyer should shop/select a company based on their tenure/value/reliability/etc. 

My fiancé and I have just finished negotiating terms on the contract and are in the process of signing on a property. We requested to use a title company that we've worked with in the past for this transaction. The agent at first agrees and fills out the contract with our requested company. However, she then comes back and says the seller "already opened title" with another company. Without knowing exactly what opening title encapsulates, I can guess that seller has essentially started processing the paperwork and such with the other company. Maybe even paid a fee. BTW the name of the company is http://onenationtitle.com.

My question is, what is the best way to navigate this snag? Should we not even worry about it? Should we negotiate to lower the purchase price to reflect the cost the seller might have incurred?

Thanks!