Exploitation is occasionally avoided in the UK through the use of genuinely altruistic donors. Where consent is not forced through economic necessity, I cannot see why donation is not a reasonable choice for a woman to make?
Objections to genuinely unforced and altruistic donation seem to arise from biological confusion and/or reductionism and treating a single cell gamete as though it were a child.
Referring to a donor's child as 'her baby' is not meaningful or scientifically accurate. Unfertilised eggs are not a potential human, and arguments that they are, are phenomenally dangerous to women, for the reasons already mentioned. Asserting donors must be mothers, and 'their children are being kept from them', is reactionary for this reason.
Eggs are single cells. Donors give tissue that would otherwise be left to decompose. One gamete contains half the genetic material needed for a potential conception. A viable embryo that successfully implants into a recipient's body is the start of the potential for a human, but whether and how that potential grows and develops, is determined by a phenomenally complex set of interactions between the bodies of the gestational mother and child as a biological system; both will be changed forever as consequences of their symbiosis. (Which is one of the reasons why surrogacy is a very different proposition).
The effect of genes upon the phenotype is mediated by the environment and the process of gene expression. This is true for all conception and at a meta level allows for evolutionary adaptations to changing environmental conditions. This includes the role of the gestational mother's homones in controlling genetic switches.
Further, as we understand more about our constitution as biological entities we think of as 'individual', but are in fact a collection of microorganisms, a further important determinant of 'individual' development is being understood; the microbial environment, which is created for the fetus by their gestational mother in utero:
The symbiotic microbiome must be understood as constituting a third set of inherited genes. In addition to the nucleus and mitochondria, the symbiotic microbiome is passed from one generation to the next (see Moran, 2007; Douglas, 2010; Gilbert, 2011)... the mammalian fetus does not just leave the uterus and passively acquire a new set of symbionts. Rather, the [gestational] mother actively passes the symbiotic baton to the developing fetus, and she doesn't relinquish control as rapidly and immediately as one might expect from the standard story. Indeed, the colonization of the body, along with the first breath that changes the circulatory system of the newborn, is possibly the most important biological aspect of birth, and the [gestational] mother will be playing an active role in this process.
(A holobiont birth narrative: the epigenetic transmission of the human microbiome, Scott F. Gilbert)
DNA does not dictate 'how we act in life' and DNA does not set our personalities. Genes have a major influence for sure, but how what is encoded in an occyte, is ultimately displayed in a phenotype (or not), is moderated in many, many different ways by environmental interactions, and the significance of that in human selfhood, is part of a much bigger story about our relationships to our physical environment, resources and our social relationships.
None of this makes exploitation of either woman OK.