You can, but you take on the commercial risk that a visa is refused after the money is spent. The safer sequence is to close into an escrow that releases the funds only when the visas are issued, which still satisfies the irrevocable-commitment rule.
Escrow keyed to visa issuance protects both sides
Consular guidance treats funds held in escrow as irrevocably committed when the sole condition of release is issuance of the visa. That lets the partners sign the purchase agreement, deposit the price and satisfy the seller's need for certainty while keeping a way back if the application fails. The escrow agreement should be explicit that the only contingency is visa issuance; a clause allowing the buyers to withdraw for other reasons weakens the commitment. If the seller refuses escrow and insists on closing, the partners can still apply, but the money is then fully at risk in the ordinary sense and a refusal leaves them owning a U.S. business they cannot run in person. Build the closing date from the consular interview availability rather than from the seller's calendar, and give the seller a firm timeline instead of a promise.
Hypothetical example: a Canadian citizen plans an acoustic-panel fabrication studio with a signed U.S. lease and equipment order. The sound sequence is to form the business, trace the lawful funds, make the commitment that exposes them to loss, assemble the operating evidence and apply through the appropriate consular process before beginning operations. An interview date and visa issuance are variables, so customer promises should be conditional. The investor may arrange the file and make lawful preliminary commitments, but should not manage production from inside the United States before admission in the appropriate status. The enterprise must be real, substantial and capable of growing beyond a minimal living.