While Dowry historically has been known in Indian society, transactional marriage is frowned upon or illegal.
The 8 forms of marriage are in general, listed here in Manu both legal and illegal. https://www.wisdomlib.org/hinduism/book/manusmriti-with-the-commentary-of-medhatithi/d/doc199792.html
The asura form of Marriage is most similar to Dowry and can be found here: https://www.wisdomlib.org/hinduism/book/manusmriti-with-the-commentary-of-medhatithi/d/doc199806.html Look at the commentary as well.
Here the asura form is legal for Vaishyas and Shudras likely being commoners and society and deep in the economics of the kingdom: https://www.wisdomlib.org/hinduism/book/manusmriti-with-the-commentary-of-medhatithi/d/doc199797.html
Here, however, it exclaims such as illegal or highly disdainful: https://www.wisdomlib.org/hinduism/book/manusmriti-with-the-commentary-of-medhatithi/d/doc199799.html
Now we move on to Mahabharata Anusasanika Parva regarding marriage: https://www.wisdomlib.org/hinduism/book/the-mahabharata-mohan/d/doc826370.html "Such sons, again, become full of malice, unrighteous in conduct, the misappropriators of other people’s wealth, and endued with deceit and cunning. Having sprung from that sinful form of marriage called Asura, the issue becomes wicked in conduct. Persons acquainted with the histories of olden times, conversant with duties, devoted to the scriptures and firm in maintaining the restraints therein laid down, recite in this connection some metrical lines sung in days of yore by Yama. Even this is what Yama had sung. That man who acquires wealth by selling his own son, or who bestows his daughter after accepting a dower for his own livelihood, has to sink in seven terrible hells one after another, known by the name of Kalasutra. There that wretch has to feed upon sweat and urine and stools during the whole time. In that form of marriage which is called Arsha, the person who weds has to give a bull and a cow and the father of the maiden accepts the gift. Some characterise this gift as a dowry (or price), while some are of opinion that it should not be regarded in that light. The true opinion, however, is that a gift for such a purpose, be it of small value or large, should, O king, be regarded as dowry or price, and the bestowal of the daughter under such circumstances should be viewed as a sale. Notwithstanding the fact of its having been practised by a few persons it can never be taken as the eternal usage. Other forms of marriage are seen, practised by men, such as marrying girls after abducting them by force from amidst their kinsmen. Those persons who have sexual intercourse with a maiden, after reducing her to subjection by force, are regarded as perpetrators of sin."
Here Bhishma infact seems to imply Arsha is equivilent to Asura forms of marriage, although this translation of Mbh isn't very good.
To sum up all forms of marriage and their morality and legality as per scriptures is debatable and some thought the very practise of accepting gifts (Arsha marriage) is sinful. While others, saw such as simply a social obligation of gift giving and not a sale or transaction and it can be very large or small.