Texas Penal Code - PENAL § 31.08. Value

(a) Subject to the additional criteria of Subsections (b) and (c), value under this chapter is:

(b) The value of documents, other than those having a readily ascertainable market value, is:

(c) If property or service has value that cannot be reasonably ascertained by the criteria set forth in Subsections (a) and (b), the property or service is deemed to have a value of $750 or more but less than $2,500.

(d) If the actor proves by a preponderance of the evidence that he gave consideration for or had a legal interest in the property or service stolen, the amount of the consideration or the value of the interest so proven shall be deducted from the value of the property or service ascertained under Subsection (a), (b), or (c) to determine value for purposes of this chapter.